Transition from fossils to renewables is leading to radical societal changes. Shifting the capital from fossils to renewables is commonly accompanied with political concerns, such as energy autonomy, domestic employment etc. Despite a decreasing trend in recent decades, energy cost remains the major bottleneck for a massive penetration of renewables, resulting in diverse policies with respect to carbon taxes and renewable subsidies. This study focuses on analysing the opportunities for Switzerland within the energy transition, through a systematic assessment on the curent petroleum supply chain with associated cost decomposition. By modeling a fossil fuels supply chain, it is within reach to estimate the final price decomposition of petroleum products. To be more precise, the aim of this study, based on open source data, is to highlight how the money spent in fossil fuels is distributed in the industry and to examine opportunities an energy transition could offer to the country in question. Applied to Switzerland, but applicable to any other country, the results show that more than 30% of the final price is spent and invested outside the country. For instance, the Swiss net import of fossil fuels alone amounted to 7.2 billions CHF in 2019. If this capital had been invested in PV, Switzerland could have produced 33.5 TWh/year, constituting 60% of Swiss electric production in 2020. In the near future, this reinvestment in PV would contribute more generally to the full development of solar energy, whose walls and roofs potential in the Swiss context is estimated to be around 67 TWh/year.